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1 The issue of generalisability Current study objectives 1. To - - PDF document

State of the ART Computational models that predict response to HIV therapy may reduce virological failure Key features of HIV Well-resourced settings Resource-limited and therapy costs in resource-limited treatment settings settings


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Revell AD, Wang D, Alvarez-Uria G, Streinu-Cercel A, Ene L, Wensing AMJ, Hamers RL, Morrow C, Wood R, Tempelman H, DeWolf F, Nelson M, Montaner JS, Lane HC, Larder BA on behalf of the RDI study group Abstract O234, 11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Computational models that predict response to HIV therapy may reduce virological failure and therapy costs in resource-limited settings

State of the ART

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Key features of HIV treatment Well-resourced settings Resource-limited settings

Strategy Individualised Public health Antiretroviral drugs

  • Approx. 25 from 6 classes

Limited availability / affordability Diagnostic & monitoring tools CD4, viral loads, resistance testing CD4 (Viral load?) Detection of failure Early – using regular viral loads Later – using CD4 counts or clinical symptoms Salvage Individualised – using genotype Standard protocol – genotypes unaffordable Expertise available High and multidisciplinary Mixed and thinly spread

  • Rapid roll-out of ART1
  • Short-term cost-savings = more patients on therapy1
  • Extended the lives of millions
  • Unnecessary treatment switching2
  • Delayed detection of failure and deferred treatment switching3
  • Increased accumulation of resistance mutations2,4
  • Loss of therapeutic options5
  • Increased morbidity/mortality4

Consequences of the public health strategy for resource-limited settings

1. World Health Organisation. Antiretroviral therapy for HIV infection in adolescents and adults: recommendations for a public health approach - 2010 revision. WHO; Geneva: 2010. 2. Sigaloff KCE, Hamers RL, Wallis CL, Kityo C, Siwale M, Ive P, et al. Unnecessary Antiretroviral Treatment Switches and Accumulation of HIV Resistance Mutations; Two Arguments for Viral Load Monitoring in Africa. J AcquirImmune Defic Syndr. 2011; 58(1):23-31. 3. Zhou J, Li P, Kumarasamy N, Boyd M, Chen Y, Sirisanthana T, et al. Deferred modification of antiretroviral regimen following documented treatment failure in Asia: results from the TREAT Asia HIV Observational Database (TAHOD). HIV medicine. 2010; 11(1):31-9. 4. KeiserO, Chi BH, GsponerT, Boulle A, Orrell C, Phiri S, et al. Outcomes of antiretroviral treatment in programmes with and without routine viral load monitoring in southern Africa. AIDS. 2011; 25(14):1761-1769. 5. Barth RE, Aitken SC, Tempelman H, Geelen SP, van Bussel E, Hoepelman AIM, et al. Accumulation of drug resistance and loss of therapeutic options precede commonly used criteria for treatment failure in HIV-1 subtype C infected patients. Antivir Ther 2012; 17:377-386 11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

A big ?

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

What can we do to maximise the long-term effectiveness of ART in RLS? How do we get the best out of a limited range of drugs? Could the individualization of salvage ART using computational models be beneficial?

  • Models can predict the response to ART with approx. 80% accuracy:

– Trained using data from many thousands of patients – Input variables including genotype, viral load, CD4 count and treatment history1,2

  • Models can predict response without a genotype with a circa 70-75%

accuracy3,4

  • At least comparable to the predictive accuracy of genotyping with rules

based interpretation (62-69%)5

  • Models now freely available via online HIV Treatment Response

Prediction System (HIV-TRePS)

Predicting response using computational models

1. Revell AD, Wang D, Boyd MA, et al. The development of an expert system to predict virological response to HIV therapy. AIDS 2011;25:1855-1863. 2. Zazzi M, Kaiser R, Sönnerborg A, et al. Prediction of response to antiretroviral therapy by human experts and by the EuResist data-driven expert system (the EVE study). HIV Med 2010; 12(4):211-218 3. Revell AD, Wang D, Harrigan R, et al. Modelling response to HIV therapy without a genotype. J Antimicrob Chemother 2010; 65(4):605-607 4. Prosperi MCF, Rosen-Zvi M, Altman A, et al. Antiretroviral therapy optimisation without genotype resistance testing. PLoS One 2010; 5(10):e13753 5. Frentz et al. Comparison of HIV-1 Genotypic Resistance Test Interpretation Systems in Predicting Virological Outcomes Over Time. PLoS One. 2010; 5(7): e11505 11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

RDI models with and without genotype and GSS from common rules systems

Larder BA et al. 49th ICAAC, 2009; H-894

Model AUC Accuracy RDI geno 0.88 82% RDI no geno 0.86 78% ANRS 0.72 66% REGA 0.68 63% Stanford db 0.71 67% Stanford ms 0.72 68%

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

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The issue of generalisability

  • Previous studies have shown that models are more accurate

for patients from ‘familiar’ settings (with data in the training set) than from unfamiliar settings

  • Our models are therefore evaluated not only during cross

validation but with independent test sets and data from other settings

International Workshop on HIV and Hepatitis Drug Resistance 2011 - abstract 34

Current study objectives

  • 1. To compare the accuracy of HIV-TRePS for

patients from ‘familiar’ settings to those from ‘unfamiliar’ resource-limited settings (RLS)

  • 2. To investigate if the system could identify

alternative regimens for cases that failed in the clinic with a higher predicted probability of success and without additional cost

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Methods 1: HIV-TRePS models

  • 10 random forest models
  • Trained with data from 14,891 cases of ART change

following virological failure in well-resourced countries

  • Input variables: viral load and CD4 count prior to treatment

change, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load.

  • Output: prediction of the probability of response to ART

(<400 copies HIV RNA/ml)

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Methods 2: Assessment of model accuracy

  • Cross-validation
  • Independent set of 800 cases from familiar settings

Unfamiliar RLS test sets

  • 231 cases from sub-Saharan Africa (5 countries)
  • 375 cases from Romania
  • 206 cases from India
  • Main outcome measure: The area under the ROC curve

(AUC)

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Results 1: Accuracy: familiar vs unfamiliar settings

DATA SET AUC Familiar RDI (n=800) 0·77

95%CI (0·73, 0·80)

Unfamiliar from RLS Southern Africa (n=231) 0·60**

95%CI (0·52, 0·69)

Romania (n=375) 0.71

95%CI (0.66, 0.76)

India (n=206) 0.63*

95%CI (0.55, 0.71) * p<0.01 vs RDI 800 **p<0.001 vs RDI 800 (de Long’s test)

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Results 2: ROC curves

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

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Methods 3: Modelling of alternative regimens

  • Baseline data input to models
  • Predictions of the probability of virological response obtained

for alternative 3-drug regimens comprising only those drugs available in the clinic

  • Is the regimen predicted to produce a virological response

(using the optimum ‘cut off’ for classifying predictions as response or failure established with the 800 RDI test set)?

  • Is the estimated probability of response higher than for the

regimen actually used in the clinic?

  • Annual therapy costs used to determine the potential cost

effectiveness of this strategy for the Indian cases

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Results 3: Modelling of alternative regimens

Southern Africa (n=231) Romania (n=375) India (n=206) Alternative regimens identified that were predicted to produce a response 217 (94%) 362 (97%) 206 (100%) No (%) of cases that failed in the clinic 63 (27%) 176 (47%) 74 (36%)

  • No. (%) of failures for which alternative

regimens were identified that were predicted to produce a response 59(94%) 164 (93%) 73(99%)

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Results 4: Modelling cost & effectiveness for India

Analysis All (n=206) Failures (n=74) 1. No (%) of alternative regimens predicted to be effective with a higher estimated probability of response than the regimen used in the clinic 175 (85%) 65 (88%) 2. No (%) of category 1 alternatives where one or more of the regimens was less costly than the regimen used in the clinic 175 (100%) 65 (100%) 3. Mean number of alternatives in category 3 10 8 5. The mean annual cost saving of the least costly regimens in category 3 $638 $555

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Conclusions 1

The HIV-TRePS models that predict virological response to ART without the need for a genotype:

  • Showed comparable accuracy to genotyping with rules-

based interpretation for patients in unfamiliar RLS

  • Were more accurate for patients from familiar than

unfamiliar settings suggesting further improvement in accuracy is possible with more data from RLS

  • Identified alternative regimens that were predicted to be

effective for the great majority of cases where the new regimen used in the clinic failed

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Conclusions 2

  • Identified cost-saving alternatives for most cases of failure

in India

  • Savings were substantial and could potentially fund

additional patients’ treatment and/or viral load monitoring

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Conclusions 3

  • The system has the potential to help optimise

antiretroviral therapy in countries with limited resources where genotyping is not generally available

  • Viral load monitoring and use of computer modelling to

individualise therapy could be a potentially cost effective alternative strategy

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

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Limitations of the study

  • Retrospective so difficult to quantify the potential impact

when used prospectively as a management tool

  • Relatively small test sets from RLS because of shortage of

data including viral load that conform to our stringent criteria

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Quotes

  • “The number one benefit of information technology is that it empowers

people to do what they want to do” Steve Ballmer, CEO of Microsoft

  • “This approach literally puts the experience of treating thousands of

different patients at the individual doctor’s fingertips.”

  • Dr. Julio Montaner, Director of the BC Centre for Excellence in HIV &

AIDS, Vancouver, Canada.

Dr Gerardo Alvarez-Uria & the team at the Rural Development Trust (RDT) Hospital, Bathalapalli, India

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

Acknowledgments 2

Dechao Wang Daniel Coe Brendan Larder

11th International Congress on Drug Therapy in HIV Infection, 11-15 November 2012; Glasgow Scotland

RDI NIAID

Cliff Lane and Julie Metcalf For funding, data and encouragement

  • AREVIR database, c/o the University of Cologne, Germany: Rolf Kaiser
  • ATHENA database c/o Netherlands HIV Monitoring Foundation, Amsterdam, The Netherlands: Frank DeWolf & Joep Lange
  • BC Centre for Excellence in HIV/AIDS: Richard Harrigan & Julio Montaner
  • Chelsea and Westminster Hospital, London: Brian Gazzard, Anton Pozniak & Mark Nelson
  • CPCRA: John Bartlett, Mike Kozal, Jody Lawrence
  • Desmond Tutu HIV Centre, Cape town, South Africa: Carl Morrow and Robin Wood
  • “Dr. Victor Babes” Hospital for Infectious and Tropical Diseases, Bucharest, Romania: Luminita Ene
  • Federal University of Sao Paulo, Sao Paulo, Brazil: Ricardo Diaz & Cecilia Sucupira
  • Fundacion IrsiCaixa, Badelona: Bonaventura Clotet & Lidia Ruiz
  • Gilead Sciences: Michael Miller and Jim Rooney
  • Hôpital Timone, Marseilles, France: Catherine Tamalet
  • Hospital Clinic Barcelona: Jose Gatell & Elisa Lazzari
  • Hospital of the JW Goethe University, Frankfurt: Schlomo Staszewski
  • ICONA: Antonella Monforte & Alessandro Cozzi-Lepri
  • Istituto Superiore di Sanità, Rome, Italy: Stefano Vella and Raffaella Bucciardini
  • Italian MASTER Cohort (c/o University of Brescia, Italy): Carlo Torti
  • Italian ARCA database, University of Siena, Siena, Italy: Maurizio Zazzi
  • The Kirby Institute, University of New South Wales, Sydney, Australia: Sean Emery and Mark Boyd
  • National Institutes of Allergy and Infectious Diseases: Cliff Lane, Julie Metcalf, Robin Dewar
  • National Institute of Infectious Diseases, Bucharest, Romania: Adrian Streinu-Cercel and Oana Streinu-Cercel
  • National Institute of Infectious Diseases, Tokyo: Wataru Sugiura
  • Ndlovu Medical Centre, Elandsdoorn, South Africa: Roos Barth & Hugo Tempelman
  • PhenGen study, Italy: Laura Monno
  • PHIDISA study, c/o National Institutes of Allergy and Infectious Diseases, Bethesda, USA: Julie Metcalf
  • Ramon y Cajal Hospital, Madrid, Spain: Maria-Jesus Perez-Elias
  • Royal Free Hospital, London, UK: Anna Maria Geretti
  • Sapienza University, Rome, Italy: Gabriella d’Ettorre
  • Tibotec Pharmaceuticals: Gaston Picchio and Marie-Pierre deBethune
  • US Military HIV Research Program: Scott Wegner & Brian Agan
  • University of Belgrade, Belgrade, Serbia: Gordana Dragovic

and a special thanks to all their patients.

Thanks to our data contributors Thanks to our data contributors